1/2 a^{a0}_{c0} b^{c1,c2}_{c4,a1} c^{c4}_{c3} eta1^{a1}_{a0} a+(c0) a+(c3) a-(c2) a-(c1)
+a^{a0}_{c2} b^{c0,c2}_{c3,a1} c^{c3}_{c1} a+(c1) a+(a1) a-(a0) a-(c0)
-a^{a0}_{c2} b^{c0,c2}_{c3,a1} c^{c3}_{c1} eta1^{a1}_{a0} a+(c1) a-(c0)
-1/2 a^{a0}_{c4} b^{c1,c2}_{c0,a1} c^{c4}_{c3} eta1^{a1}_{a0} a+(c0) a+(c3) a-(c2) a-(c1)
+a^{a0}_{c4} b^{c1,c4}_{c0,a1} c^{c3}_{c2} eta1^{a1}_{a0} a+(c0) a+(c2) a-(c3) a-(c1)